The invention relates to the repair and patching of damaged interior walls such as drywall, sometimes called Sheetrock. Typical dry wall construction involves the attachment of drywall to two by four studs on 16 inch centers. The dry wall is a material made of plaster of Paris or the like sandwiched between carboard inner and outer surfaces. The mateial is quite brittle and may be easily damaged by a sharp blow from even a blunt object such as a door handle or the corners of a piece of furniture.
The traditional method of repair of holes in drywall includes placing a backing plate behind the drywall and then filling in the hole with a spackling compound or with plaster of Paris. This method of repair requires a plurality of steps that span several days in time. First the original filling needs a day or so to dry and on drying some shrinkage usually occurs. The patch must then be sanded and a second layer used to level the hole. After another day or so elapses, the patch on the wall is finally ready to paint.
In order to simplify the patching of holes in drywall construction, drywall patches have been invented. Hoffmann, U.S. Pat. No. 4,135,017, discloses a patch strengthened by a thin gage aluminum sheet which can be bonded to a wall using a two-sided adhesive tape. The exterior surface of Hoffmann's patch is covered with a fibrous material of sufficient porosity to allow a wall finishing compound to be bonded to it. To effect a smooth and invisible repair, one usually must apply a thin coating of plaster to this fibrous material. The Hoffmann invention, although offering an improvement over past methods, still requires a long time delay while the coating of plaster on the patch dries. Furthermore, if an area covered by Hoffmann's patch is struck, its thin metal substrate will probably deform permanently and therefore need to be repaired.